摘要
对两种典型无烟煤进行了工业分析及热重试验,应用双混合分数(PDF)模型对不同无烟煤掺烧方式下直吹式制粉系统W型火焰锅炉进行了数值模拟,得到了炉内烟气温度场、氧体积分数分布场及烟气速度场.结果表明:两种无烟煤的工业分析参数基本相当,但可磨性和燃烧特性存在明显差异;在炉前掺烧方式下,炉膛温度、氧体积分数分布以及速度场均较对称,但煤粉燃尽率比分磨掺烧方式下明显偏低,炉膛出口烟气温度比分磨掺烧方式下偏高;在分磨掺烧方式下,磨煤机运行模式对燃烧经济性有较大影响;无烟煤与无烟煤也存在混煤掺烧优化的空间,分磨掺烧方式可提高燃烧经济性.
Proximate analysis and thermogravimetric tests were carried out to two typical kinds of anthracite,while numerical simulation performed on blended coal combustion with anthracite in a direct-fired pulverizing system for W-shaped flame boilers at different coal blending modes using dual-mixture fraction/PDF approach,during which the in-furnace temperature field,oxygen concentration distribution and velocity field were obtained.Results show that the proximate analysis data for above two kinds of anthracite are basically the same,but their grindability and combustion characteristics are quite different.At the combustion mode of ＂blending before furnace＂,the in-furnace temperature field,oxygen concentration distribution and velocity field are quite symmetrical,but the burn-off degree of coal powder is lower and the furnace outlet temperature is higher than the mode of ＂pulverizing coal in different mills＂.At the combustion mode of ＂pulverizing coal in different mills＂,the operation pattern of coal mill affects the combustion economy greatly,in which case optimization is possible even under the condition that one kind of anthracite is blended with another,therefore the combustion mode of ＂pulverizing coal in different mills＂ is believed to be beneficial for improvement of the combustion economy.
出处
《动力工程学报》
CAS
CSCD
北大核心
2012年第5期345-350,367,共7页
Journal of Chinese Society of Power Engineering
关键词
W型火焰锅炉
直吹式制粉系统
无烟煤
混煤掺烧
数值模拟
W-shaped flame boiler； direct-fired pulverizing system； anthracite； blended coal combustion； numerical simulation
